weft

What it is

.weft files declare types, structs, protocols, services and views, and annotate them with the institutional knowledge that usually lives in prose: @Rule for an invariant, @Decision for a rationale, @Role for the Clean Architecture layer a thing belongs to, @Implements to say which rule a piece of code satisfies. The toolchain — a CLI, a language server, a tree-sitter grammar with VS Code and Zed extensions, and an MCP server — then validates the spec: broken references, unimplemented rules, layer violations, all reported like compiler errors.

What is interesting

The architecture is the kind you hope to find and rarely do: lexer → parser → AST → analyzer → CLI and server, each stage with one job, a recursive-descent parser written by hand, and a build-freshness check that refuses to run stale code. Its contract and bootstrap commands exist to hand a downstream coding agent grounded facts instead of letting it re-derive them from prose.

Status, honestly

It installs, builds, and passes all 33 tests today after six months dormant; every documented command works. But the core bet — that a small team needs a bespoke syntax to keep design docs honest — has been undercut by the arrival of agents that can read plain markdown and catch the same drift. What survives is a narrow, real niche: deterministic, free, offline validation that cannot hallucinate. We keep it as a finished experiment, not a product.